The present invention relates to the field of phenyl oxazolidinone compounds having antibacterial activity against Gram-positive and Gram-negative bacteria, pharmaceutical compositions containing the compounds, and methods of treating bacterial infections with the compounds.
Oxazolidinones have been identified, within the last twenty years, as a new class of antibacterials which are active against numerous multidrug-resistant gram positive organisms. Particularly problematic pathogens include methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-intermediate resistant Staphylococcus aureus (GISA), vancomycin-resistant enterocci (VRE) and penicillin- and cephalosporin-resistant Streptococcus pneumoniae. As a class, oxazolidinones exhibit a unique mechanism of action. Studies have shown that these compounds selectively bind to the 50S ribosomal subunit and inhibit bacterial translation at the initiation phase of protein synthesis. Exemplary members of oxazolidinones are linezolid (see WO 95/07271) and eperezolid. 
U.S. Pat. No. 5,792,765 to Riedl et al. discloses a series of substituted oxazolidinones (cyanoguanidine, cyanoamidines, and amidines) useful as antibacterial medicaments.
U.S. Pat. No. 5,910,504 to Hutchinson discloses a series of hetero-aromatic ring substituted phenyl oxazolidinones, including indolyl substituted compounds useful as antibacterial agents.
WO 98/54161 (Hester et al.) discloses amides, thioamides, ureas, and thioureas which are antibacterial agents.
WO 95107271 (Barbachyn et al.) discloses oxazine and thiazine oxazolidinone derivatives such as linezolid and its analogs which are useful antimicrobial agents, effective against a number of human and veterinary pathogens, including gram-positive aerobic bacteria such as multiple-resistant staphylococci, streptococci and enterococci as well as anaerobic organisms such as Bacteroides spp. and Clostridia spp. species, and acid-fast organisms such as Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium spp.
WO 93/09103 (Barbachyn et al.) discloses substituted aryl- and heteroarylphenyloxazolidinones which are useful as antibacterial agents.
The invention provides phenyl oxazolidinone compounds of Formula I: 
wherein:
R is selected from the group consisting of OH, O-Aryl, O-Heteroaryl, N3, ORxe2x80x2, OSO2Rxe2x80x3, xe2x80x94NRxe2x80x2xe2x80x3Rxe2x80x3xe2x80x3, or 
xe2x80x83wherein:
(i) Rxe2x80x2 is straight-chain or branched acyl having up to 6 carbon atoms or benzyl;
(ii) Rxe2x80x3 is straight-chain or branched alkyl, having up to 5 carbon atoms, phenyl or tolyl; and
(iii) Rxe2x80x2xe2x80x3 and Rxe2x80x3xe2x80x3 are independently selected from the group consisting of H, cycloalkyl having 3 to 6 carbon atoms, phenyl or tert-butoxycarbonyl, fluorenyloxycarbonyl, benzyloxycarbonyl, straight-chain or branched alkyl having up to 6 carbon atoms which is optionally substituted by cyano or alkoxycarbonyl having up to 4 carbon atoms, xe2x80x94CO2xe2x80x94R1, xe2x80x94COxe2x80x94R1, xe2x80x94CSxe2x80x94R1, and xe2x80x94SO2xe2x80x94R4, in which
R1 is selected from the group consisting of H, cycloalkyl having 3 to 6 carbon atoms, trifluoromethyl or phenyl, benzyl or acyl having up to 5 carbon atoms, straight-chain or branched alkyl having up to 6 carbon atoms, said alkyl optionally substituted by straight-chain or branched alkoxycarbonyl having up to 5 carbon atoms, OH, cyano, up to 3 halogen atoms, and xe2x80x94NR5 R6 in which R5 and R6 are identical or different and are selected from H, phenyl or straight-chain or branched alkyl having up to 4 carbon atoms;
R4 is selected from straight-chain or branched alkyl having up to 4 carbon atoms or phenyl and:
R4a is CN, COR4c, COOR4c, CONHR4c, COxe2x80x94NR4c R4d, SO2R4c, or NO2;
R4b is H, alkyl, OR4c, SR4c, amino, NHR4c, NR4c,R4d;
R4c and R4d are independently selected from H, alkyl, aryl, or in the case of any NR4cR4d group R4c and R4d taken together with the nitrogen atom to which they are attached form a unsubstituted or substituted pyrrolidinyl, piperidinyl or morpholinyl group;
X is 0 to 4 members independently selected from the group consisting of halogen, OH, nitro, C1-8 alkoxy, C1-8 alkyl-amino, di(C1-8-alkyl-)amino, carboxy, alkoxycarbonyl, C1-8 alkyl-COxe2x80x94Oxe2x80x94, C1-8 alkyl-COxe2x80x94NHxe2x80x94, carboxamide, CN, amine, C3-6 cycloalkyl, C1-8 alkyl optionally substituted with one or more members selected from the group consisting of F, Cl, OH; and
Y is a radical of Formulae II or III: 
xe2x80x83wherein
R5, R6, R7, and R8 are each independently H, alkyl, CN, nitro, C1-8 alkyl, halo-C1-8-alkyl, formyl, carboxy, alkoxycarbonyl, carboxamide, or R5 and R6 and/or R7 and R8 together form an oxo group;
R9, and R10 are each independently H, halogen, alkyl, OH, CN, nitro, C1-8 alkyl, halo-C1-8-alkyl, C1-8 alkoxyl, amino, C1-8-alkyl-amino, di(C1-8-alkyl-)amino, formyl, carboxy, alkoxycarbonyl, C1-8-alkyl-COxe2x80x94Oxe2x80x94, C1-8-alkyl-COxe2x80x94NHxe2x80x94, carboxamide, or amine;
 is a fused phenyl ring or a five- or six-membered heteroaromatic ring having one to four members selected from the group consisting of S, O, and N;
Z is halogen, alkyl, substituted-alkyl, aryl, substituted-aryl, heteroaryl, substituted-heteroaryl, CN, CHO, COalkyl, amino, alkoxy, HNCOxe2x80x94(C1-C8alkyl), allyl, propargyl, allenyl, or N-alkylthiocarbamoyl;
and
m is 0 or 1,
and the pharmaceutically acceptable salts and esters thereof.
Compounds of the above formula are useful as antibacterial agents for the treatment of bacterial infections in humans and animals.
The present invention is also directed to a method of treating a subject having a condition caused by or contributed to by bacterial infection, which comprises administering to said mammal a therapeutically effective amount of the compound of Formula I.
The present invention is further directed to a method of preventing a subject from suffering from a condition caused by or contributed to by bacterial infection, which comprises administering to the subject a prophylactically effective dose of the pharmaceutical composition of a compound of Formula I.
Other objects and advantages will become apparent to those skilled in art from a review of the ensuing specification.
Relative to the above description of the phenyl oxazolidinone compounds of the present invention, the following definitions apply.
Unless specified otherwise, the terms xe2x80x9calkylxe2x80x9d, xe2x80x9calkenylxe2x80x9d, and xe2x80x9calkynylxe2x80x9d may be straight or branched groups with 1-8 carbon atoms.
xe2x80x9cSubstituted alkylxe2x80x9d may be a straight or branched-chain moiety with 1-8 carbon atoms having one or more substituents selected from the group consisting of amino, dialkylamino, cycloalkyl, hydroxy, oxo, alkoxycarbonyl, benzyloxy, arylthio, alkylthio, hydroxyalkylthio, alkylsulfinyl, alkylsulfonyl, carboxy, phosphonooxy, dialkylphosphonooxy, dibenzylphosphonooxy, cyano, halo, trialkylsilyl, dialkylphenylsilyl, aryl, heteroaryl, heterocyclo, heterocyclomethylbenzoyloxy, dialkylaminomethylbenzoyloxy, dialkylaminoalkylcarbonyloxy, benzyloxycarbonylaminoalkylcarbonyloxy, and aminoalkylcarbonyloxy.
xe2x80x9cAcylxe2x80x9d means an organic radical having the designated number of carbon atoms, derived from an organic acid by the removal of a hydroxyl group having the formula RCO, as in the case of acetyl where R is CH3.
xe2x80x9cArylxe2x80x9d is an unsubstituted carbocyclic aromatic group including, but not limited to, phenyl, 1- or 2-naphthyl and the like. xe2x80x9cHeteroarylxe2x80x9d refers to a cyclic aromatic radical having from five to ten atoms in the ring; where one to three ring atoms are independent heteroatoms such as S, O, and N, and the remaining ring atoms are carbon, for example, a pyridinyl, pyrazinyl, pyrimidinyl, pyrroyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isoxazolyl, thiadiazolyl, oxadiazolyl, thienyl, furanyl, quinolinyl, or isoquinolinyl, radical and the like.
xe2x80x9cSubstituted arylxe2x80x9d or xe2x80x9csubstituted heteroarylxe2x80x9d refers to an aryl or heteroaryl substituted by independent replacement of 1-3 of the hydrogen atoms thereon with halogen, OH, CN, mercapto, nitro, C1-8-alkyl, halo-C1-8-alkyl, C1-8-alkoxy, thio-C1-8-alkyl, amino, C1-8-alkyl-amine, di(C1-C8-alkyl-)amino, formyl, carboxy, alkoxycarbonyl, C1-8-alkyl-COxe2x80x94Oxe2x80x94, C1-8-alkyl-COxe2x80x94NHxe2x80x94, or carboxamide. Further, substituted-heteroaryl may be substituted with a mono-oxo to give, for example, a 4-oxo-1-H-quinoline. Substituted-heteroaryl may also be substituted with a substituted-aryl or a second substituted-heteroaryl to give, for example, a 4-phenyl-imidazol-1-yl or a 3-pyridinyl-imidazol-1-yl, and the like.
The terms xe2x80x9cheterocycle,xe2x80x9d xe2x80x9cheterocyclic,xe2x80x9d and xe2x80x9cheterocycloxe2x80x9d refer to an optionally substituted, fully saturated, partially saturated, or non-aromatic cyclic group which is, for example, a 3- to 7-membered monocyclic, 7- to 11-membered bicyclic, or 10- to 15-membered tricyclic ring system, which has at least one heteroatom in at least one carbon atom containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2, or 3 heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms, where the nitrogen and sulfur heteroatoms may also optionally be oxidized. The nitrogen atoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom.
The term xe2x80x9chaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d means fluoro, chloro, bromo and iodo. (mono-, di-, tri-, and per-) halo-alkyl is an alkyl radical substituted by independent replacement of the hydrogen atoms thereon with halogen. P denotes phosphorus.
The compounds of the instant invention are asymmetric in the oxazolidinone ring at the 5- position and thus exist as optical antipodes. As such, all possible optical antipodes, enantiomers or diastereomers resulting from additional asymmetric centers that may exist in optical antipodes, racemates and racemic mixtures thereof are also part of this invention. The antipodes can be separated by methods known to those skilled in the art such as, for example, fractional recrystallization of diastereomeric salts of enantiomerically pure acids. Alternatively, the antipodes can be separated by chromatography on a Pirkle column.
The phrase xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d denotes salts of the free base which possess the desired pharmacological activity of the free base and which are neither biologically nor otherwise undesirable. These salts may be derived from inorganic or organic acids. Examples of inorganic acids are hydrochloric acid, nitric acid, hydrobromic acid, sulfuric acid, or phosphoric acid. Examples of organic acids are acetic acid, propionic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, methyl sulfonic acid, salicyclic acid and the like. Suitable salts are furthermore those of inorganic or organic bases, such as KOH, NaOH, Ca(OH)2, Al(OH)3, piperidine, morpholine, ethylamine, triethylamine and the like.
Also included within the scope of the invention are the hydrated forms of the compounds which contain various amounts of water, for instance, the hydrate, hemihydrate and sesquihydrate forms.
The term xe2x80x9csubjectxe2x80x9d includes, without limitation, any animal or artificially modified animal. In the preferred embodiment, the subject is a human.
The term xe2x80x9cdrug-resistantxe2x80x9d or xe2x80x9cdrug-resistancexe2x80x9d refers to the characteristics of a microbe to survive in presence of a currently available antimicrobial agent at its routine, effective concentration.
The compounds of the present invention possess antibacterial activity against Gram-positive and certain Gram-negative bacteria. They are useful as antibacterial agents for the treatment of bacterial infections in humans and animals. Particularly, these compounds have antimicrobial activity against S. aureus, S. epidermidis, S. pneumoniae, E. faecalis, E. faecium, Moraxella catarrhalis, and H. influenzae. More particularly, these compounds are useful against resistant bacteria such as MRSA and GISA, and have a low susceptibility to acquired resistance mechanisms.
Compounds of Formula I which are preferred for such purposes are those in which R is any of the following: 
In addition Compounds of Formula I which are preferred for such purposes are those in which Y is any of the following: 
In addition, Compounds of Formula I which are preferred for such purposes or those in which Z is any of the following: propargyl, allyl, allenyl, N-alkylthiocarbamoyl, alkyl, heteroaryl, substituted-heteroaryl, or a substituted alkyl having one or more substituents selected form the group consisting of amino, dialkylamino, cycloalkyl, hydroxy, oxo, alkoxycarbonyl, benzyloxy, arylthio, alkylthio, hydroxyalkylthio, alkylsulfinyl, alkylsulfonyl, carboxy, phosphonooxy, dialkylphosphonooxy, dibenzylphosphonooxy, cyano, halo, trialkylsilyl, dialkylphenylsilyl, aryl, heteroaryl, heterocyclo, heterocyclomethylbenzoyloxy, dialkylaminomethylbenzoyloxy, dialkylaminoalkylcarbonyloxy, benzyloxycarbonylaminoalkylcarbonyloxy, and aminoalkylcarbonyloxy.
Particularly preferred Compounds of Formula I are those wherein Z is selected from the group consisting of propargyl, allyl, allenyl, N-alkylthiocarbamoyl, ethyl, isopropyl, t-butyl, 2-hydroxyethyl, 3-hydroxypropyl, 2,2,2-trifluoroethyl, cyanomethyl, 2-cyanoethyl, cyclopropylmethyl, 2-oxopropyl, methylthiomethyl, 2-methylthioethyl, methylsulfonylmethyl, 2-methylsulfonylethyl, methylsulfinylmethyl, t-butoxycarbonylmethyl, 2-carboxyethyl, 2-(di-t-butylphosphonooxy)ethyl, 2-(dibenzylphosphonooxy)ethyl, 2-phosphonooxyethyl, 2-aminoethyl, 2-(diethylamino)ethyl, 2-(dimethylamino)ethyl, 2-(4-morpholinyl)ethyl, 2-(4-thiomorpholinyl)ethyl, trimethylsilylmethyl, dimethylphenylsilylmethyl, benzyloxymethyl, benzyl, 5-tetrazolylmethyl, 3-pyridylmethyl, 2-pyridylmethyl, 2-oxiranylmethyl, 2-oxooxazolidin-5-ylmethyl, 2,3-dihydroxypropyl, 2-hydroxy-3-(1-piperidinyl)propyl, 2-hydroxy-3-(4-morpholinyl)propyl, 2-hydroxy-3-phenylthiopropyl, 2-hydroxy-3-ethylthiopropyl, 2-hydroxy-3-(2-hydroxyethylthio)propyl, 3-[4-(1,1-dioxothiomorpholinyl)]-2-hydroxypropyl, 3-ethylsulfinyl-2-hydroxypropyl, 2-[4-(4-morpholinylmethyl)benzoyloxy]ethyl, 2-[4-(dimethylaminomethyl)benzoyloxy]ethyl, 2-[4-(4-methyl-1-piperazinylmethyl)benzoyloxy]ethyl, 2-(dimethylaminoacetoxy)ethyl, 2-[2-(benzyloxycarbonylamino)-3-methylbutyryloxy]ethyl, 2-(2-amino-3-methylbutyryloxy)ethyl, 2-pyridinyl, pyridazinyl, and 2-pyrimidinyl.
Particular examples of the present invention include the following compounds:
N-[[(5S)-3-[4-(1,3-Dihydro-2H-isoindol-2-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-(1,3-Dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[3-Fluoro-4-(5-oxido-2H-pyrrolo[3,4-c]pyridin-2-yl)phenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-(5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-(1,3-dihydro-1-oxo-2H-isoindol-2-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide; and
(5R)-3-[4-(5,7-Dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)-3-fluorophenyl]-5-(hydroxymethyl)-2-oxazolidinone;
N-[[(5S)-3-[4-[2,6-dihydro-2-(2-hydroxyethyl)pyrrolo[3,4-c]pyrazol-5(4H)-yl]-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-[2,6-dihydro-2-[(2R)-2,3-dihydroxypropyl]pyrrolo[3,4-c]pyrazol-5(4H)-yl]-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-[2,6-dihydro-2-[(2S)-2,3-dihydroxypropyl]pyrrolo[3,4-c]pyrazol-5(4H)-yl]-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-(2,6-dihydro-2-propargylpyrrolo[3,4-c]pyrazol-5(4H)-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
N-[[(5S)-3-[4-(2,6-dihydro-2-cyanomethylpyrrolo[3,4-c]pyrazol-5(4H)-yl)-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]acetamide;
The compounds of Formula I that are the subject of this invention may be prepared from readily available starting materials such as isoindole (Gawley et al., J. Org. Chem., 1988, 53:5381), 6,7-dihydro-5H-pyrrolo[3,4-c]pyridine and 6,7-dihydro-5H-pyrrolo[3,4-b]pyridine (U.S. Pat. No. 5,371,090 to Petersen et al.) in accordance with synthetic methods well known in the art. Representative procedures are outlined in Scheme I-V: 
In accordance with Scheme I, bicyclic heterocycles of general formula IV are treated with a substituted nitrobenzene derivative (L is an appropriate leaving group such as a halogen of trifluoromethanesulfonyloxy) in a suitable base and solvent such as diisopropylamine and ethyl acetate, to give the substituted nitrophenyl compound V.
The nitrobenzene derivative V is then reduced to the aniline by an appropriate reaction, for instance by treatment with SnCl2 or by catalytic hydrogenation in the presence of a suitable catalyst, such as palladium on carbon. The aniline is then treated with benzyl or methyl chloroformate and sodium bicarbonate to form the corresponding benzyl or methyl carbamate derivative VI.
The Cbz aniline VI is then deprotonated with a lithium base such as n-butyllithium and reacted with (R)- glycidyl butyrate to afford the oxazolidinone VII. The hydroxymethyl group can then be converted to an amide as shown in Scheme I by preparation of the mesylate, conversion to azide VIII, and reduction to amine IX by an appropriate procedure such as hydrogenation. Alternatively displacement of a mesylate (Scheme II) or appropiate leaving group such as tosylate or chlorine with potassium phthalimide and removal of the phthaloyl protecting group by hydrazinolysis would provide amine IX. The amine IX can be converted to amide X by an acylation reaction using techniques known in the art, such as treatment with acetic anhydride in the presence of a base such as pyridine. Alternatively, amine IX can be converted to a carbamate XI by treatment with methylchloroformate and pyridine, or reacted with a sulfonyl chloride in an inert solvent in the presence of an organic base like pyridine to form a sulfonamide XII 
For the formation of oxazolidione in which Rxe2x95x90O-Heteroaryl (XIII), the oxazolidinone carbinol VII can be converted to the corresponding mesylate or other appropriate leaving group and reacted with HO-Het (a suitible hydroxyl containing heterocycle), either in the presence of base or with HO-Het as a preformed alkoxide, in an appropriate solvent, for example DMF or acetonitrile (Scheme III). Alternatively, Mitsunobu conditions can be used to couple VII with HO-Heterocycle by treating with triphenyiphosphine and diisopropyl azodicarboxylate (DIAD) in an appropriate solvent, such as THF, at a suitable temperature, preferably room temperature. Reaction conditions and leading references can be found in Gravestock et al, WO99/64416.
Furthermore, by treating VII with a suitable, non-nucleophilic base, for example NaH, the displacement of a leaving group (LG), such as chlorine or bromine, can be effected from an appropriately reactive aza-heterocycle (LG-Het)(Scheme III). 
Compounds of structure XIV can be prepared as shown in Scheme IV. Amine IX can be converted to various functionalized amidines by reaction with activated imines, where Q is a leaving group such as methylthio or methoxy, in a suitable solvent, for example toluene or methanol, with or without a catalyst (such AgNO3) present at a temperature range of 0-110xc2x0 C. 
In accordance with Scheme V pyrrolidinone XV (prepared as in WO96/13502) is first reacted with methoxy-bis(dimethylamine) or other activated dimethylformamide reagent and, second, heated in a suitable solvent (for example DMF and benzene) with either substituted amidines, to form pyrrolopyrimidines oxazolidinones such as XVI, or substituted hydrazines, to form pyrrolopyrazole oxazolidinones such as XVII. Formation of thexe2x80x94enamine, alkoxymethylene or alkoxycarbonyl derivatives of pyrrolidinone XV, according to Brighty et al in U.S. Pat. No. 5,037,834A, would also allow access to these systems. 
As shown in Scheme VI compounds with the structure XIX can be achieved by oxidation of the various compounds, XVIII, using an appropriate oxidant (for example manganese dioxide, peroxyacetic acid, DDQ or air) in a suitable solvent such as methylene chloride. 
Oxo-derivatives of structure XXII in Scheme VII, (Xxe2x95x90O, Yxe2x95x90H2 or Xxe2x95x90H2, Yxe2x95x90O) can be constructed by reacting 1,2-aryl dicarboxaldehydes (where XXI, Uxe2x95x90H) with aniline XX (prepared as in WO96/23788) in the presence of acids, such as acetic acid, in a suitable solvent such as methylene chloride. The di-oxo-derivatives (structure XXII where Xxe2x95x90Yxe2x95x90O) are prepared from the reaction of aniline XX with selected 1,2-aryl dicarbonyl reagents with a suitable leaving group (XXI where Uxe2x95x90Cl, Br, etc). 
Compounds of the structure XXIV and XVII can be prepared as shown in Scheme VIII. Pyrazole XXIII can be converted to regioisomeric alkylated pyrazoles by reaction with a base, such as potassium tert-butoxide , sodium hydride, or cesium carbonate, and an alkylating agent, such as an alkyl halide. 
Pyrazole XXV can be further functionalized (Scheme IX) by conversion of the hydroxyl group to an appropriate leaving group, such as mesylate or halide, and displacement with nucleophiles, such as an amine, thiol, etc to afford substituted pyrazoles such as XXVI where X represents nitrogen, sulfur, etc. 
Various derivatives [amino acid (XXVII), phosphate (XXVIII) and substituted benzoic acid (XXIX)] with greater aqueous solubility can be prepared as illustrated in Scheme X. Coupling of pyrazole XXV with an amino acid derivative can be accomplished using a coupling reagent, such as EDCI and DMAP. Following coupling, the amino acid protecting groups can be remove (if so desired) by standard literature methods known to those skilled in the art. Phosphate derivative XXVIII can be prepared by a three-step procedure via reaction of pyrazole XXV with dialkyl(dialkylamino)phosphite and tetrazole, oxidation of the phosphorous with meta-chloroperoxybenzoic acid and removal of tert-butyl protecting groups with acid, such as TFA in methylene chloride. Water soluble benzoic acid derivative XXIX can be prepared by initial coupling of pyrazole XXV with 2-(chloromethyl)benzoyl chloride, utilizing triethyl amine as base, and then displacement of the halide with an amine, such morpholine, dimethylamine and the like, employing sodium iodide as a catalyst. 
Substituted 2-hydroxy propyl pyrazoles can be prepared through attack on the epoxide functionality of Compound XXX with various nucleophiles, such an amine, thiol, etc. to provide pyrazoles such as XXXI where X represents nitrogen, sulfur, etc (Scheme XI). The sulfur containing analogs, represented by Compound XXXII where X represents an inert linking group (Scheme XII), can be further functionalized by reaction with oxidizing agent, such as meta-chloroperoxybenzoic acid or tetrabutylammonium oxone, to provide sulfoxide or sulfone analogs, such as XXXIII. 
Tetrazole XXXV can be prepared by reaction of nitrile XXXIV with azidotrimethylsilane and catalytic dibutyltinoxide provides tetrazole (Scheme XIII). 
Definitions
All temperatures are in degrees Centigrade
Brine refers to an saturated aqueous sodium chloride solution
DMF refers to N,N-dimethylformamide
THF refers to tetrahydrofuran
Cbz refers to carbobenzyloxy
n-BuLi refers to n-butyl lithium
MS refers to mass spectrometry expressed as mile or mass/charge unit
[M+H] refers to the positive ion of a parent plus a hydrogen atom
Ether refers to diethyl ether
RT refers to room temperature
Mp refers to melting point
CH2Cl2 refers to methylene chloride
NaOH refers to sodium hydroxide
MeOH refers to methanol
EtOAc refers to ethyl acetate
ppt refers to a precipitate
These compounds have antimicrobial activity against susceptible and drug resistant bacterial pathogens such as S. aureus, S. epidermidis, S. pneumoniae, S. pyogenes, Enterococcus spp., Moraxella catarrhalis and H. influenzae. These compounds are particularly useful against drug resistant Gram-positive cocci such as methicillin-resistant S. aureus and vancomycin-resistant enterococci. These compounds are useful in the treatment of community-acquired pneumonia, upper and lower respiratory tract infections, skin and soft tissue infections, hospital-acquired lung infections, bone and joint infections, and other bacterial infections.
Minimal inhibitory concentration (MIC) has been an indicator of in vitro antibacterial activity widely used in the art. The in vitro antimicrobial activity of the compounds was determined by the microdilution broth method following the test method from the National Committee for Laboratory Standards (NCCLS). This method is described in the NCCLS Document M7-A4, Vol.17, No.2, xe2x80x9cMethods for Dilution Antimicrobial Susceptibility Test for Bacteria that Grow Aerobicallyxe2x80x94Fourth Editionxe2x80x9d, which is incorporated herein by reference.
In this method two-fold serial dilutions of drug in cation adjusted Mueller-Hinton broth are added to wells in microdilution trays. The test organisms are prepared by adjusting the turbidity of actively growing broth cultures so that the final concentration of test organism after it is added to the wells is approximately 5xc3x97104 CFU/well.
Following inoculation of the microdilution trays, the trays are incubated at 35xc2x0 C. for 16-20 hours and then read. The MIC is the lowest concentration of test compound that completely inhibits growth of the test organism. The amount of growth in the wells containing the test compound is compared with the amount of growth in the growth-control wells (no test compound) used in each tray. As set forth in Table 1, some compounds of the present invention were tested against a variety of pathogenic bacteria resulting in a range of activities, from 1 to xe2x89xa7128 xcexcg/mL depending on the organism tested. S. aureus OC2878 is a MRSA and E. faecium OC3312 is a vancomycin resistant enterococcus.
This invention further provides a method of treating bacterial infections, or enhancing or potentiating the activity of other antibacterial agents, in a subject having conditions caused by or contributed to by bacterial infection, which comprises administering to the animals a compound of the invention alone or in admixture with another antibacterial agent in the form of a medicament according to the invention. The terms of xe2x80x9ctreatingxe2x80x9d and xe2x80x9ctreatmentxe2x80x9d include administering, either simultaneously, separately or sequentially, a pharmaceutically effective amount of a composition containing one or more of the compounds disclosed herein to a subject that desires inhibition of bacterial growth. The pharmaceutically effective amount of the compound used to practice the present invention for treatment varies depending on the manner of administration, the age, weight, and general health of the subject treated, and ultimately will be decided by physicians or veterinarians.
The compounds of the present invention may be administered to a subject such as a human by any route appropriate to the condition to be treated, suitable routes including oral, rectal, nasal, topical (including buccal and sublingual), vaginal and parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intrathecal and epidural). The preferred route may vary with, for example, the condition of the recipient as well as the ease of preparation and administration.
When the compounds are employed for the above utility, they may be combined with one or more pharmaceutically acceptable carriers, e.g., solvents, diluents, and the like, and may be administered orally in such forms as tablets, capsules, dispersible powders, granules, or suspensions containing for example, from about 0.5% to 5% of suspending agent, syrups containing, for example, from about 10% to 50% of sugar, and elixirs containing, for example, from about 20% to 50% ethanol, and the like, or parenterally in the form of sterile injectable solutions or suspensions containing from about 0.5% to 5% suspending agent in an isotonic medium. These pharmaceutical preparations may contain, for example, from about 0.5% up to about 90% of the active ingredient in combination with the carrier, more usually between 5% and 60% by weight.
Compositions for topical application may take the form of liquids, creams or gels, containing a therapeutically effective concentration of a compound of the invention admixed with a dermatologically acceptable carrier.
In preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed. Solid carriers include starch, lactose, dicalcium phosphate, microcrystalline cellulose, sucrose and kaolin, while liquid carriers include sterile water, polyethylene glycols, non-ionic surfactants and edible oils such as corn, peanut and sesame oils, as are appropriate to the nature of the active ingredient and the particular form of administration desired. Adjuvants customarily employed in the preparation of pharmaceutical compositions may be advantageously included, such as flavoring agents, coloring agents, preserving agents, and antioxidants, for example, vitamin E, ascorbic acid, BHT and BHA.
The preferred pharmaceutical compositions from the standpoint of ease of preparation and administration are solid compositions, particularly tablets and hard-filled or liquid-filled capsules. Oral administration of the compounds is preferred. These active compounds may also be administered parenterally or intraperitoneally. Solutions or suspensions of these active compounds as a freebase or pharmacological acceptable salt can be prepared in water suitably mixed with a surfactant such as hydroxypropyl-cellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols and mixtures thereof in oils. Under ordinary conditions of storage and use, these preparations may contain a preservative to prevent the growth of microorganisms.
The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils.
The effective dosage of active ingredient employed may vary depending on the particular compound employed, the mode of administration and the severity of the condition being treated. However, in general, satisfactory results are obtained when the compounds of the invention are administered at a daily dosage of from about 0.1 mg/kg to about 400 mg/kg of animal body weight, preferably given in divided doses two to four times a day, or in sustained release form. For most large mammals the total daily dosage is from about 0.07 g to 7.0 g, preferably from about 100 mg to 1000 mg. Dosage forms suitable for internal use comprise from about 100 mg to 500 mg of the active compound in intimate admixture with a solid or liquid pharmaceutically acceptable carrier. This dosage regimen may be adjusted to provide the optimal therapeutic response. For example, several divided doses may be administered daily or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation.
The production of the above-mentioned pharmaceutical compositions and medicaments is carried out by any method known in the art, for example, by mixing the active ingredients(s) with the diluent(s) to form a pharmaceutical composition (e.g. a granulate) and then forming the composition into the medicament (e.g. tablets).
The following examples describe in detail the chemical synthesis of representative compounds of the present invention. The procedures are illustrations, and the invention should not be construed as being limited by chemical reactions and conditions they express. No attempt has been made to optimize the yields obtained in these reactions, and it would be obvious to one skilled in the art that variations in reaction times, temperatures, solvents, and/or reagents could increase the yields.